??? ?? ??? ???? ??? ???????

login.php ??? ??? ????.

<?php
    // 鏈接數(shù)據(jù)庫
    session_start();
    require_once('conn.php');

    //獲取表單的信息
    $name = trim($_POST['username']);
    $password = md5($_POST['password']);
    $_SESSION['username'] = trim($_POST['username']);
    $_SESSION['password'] = trim($_POST['username']);

    //查詢數(shù)據(jù)庫  然后取出數(shù)據(jù)庫的信息，如果和表單提交的信息一致，則登錄成功，進入后臺管理
    $sql = "select * from user where username='$name' and password='$password'";
    $res = mysql_query($sql);
    $row = mysql_fetch_row($res);
    if($row){
        echo "<script>alert('登錄成功')</script>";
        echo "<script>location.href='main.php'</script>";
    }else{
        echo "<script>alert('登錄失敗')</script>";
        echo "<script>history.go(-1);</script>";   //登錄失敗返回上一個頁面
    }
?>

? ??? ????, log.php ??? ?? login.php? ?????. login.php ?? form

? ?? ??? ??? seesion

? ?????. $_SESSION['username'] = Trim($_POST['username']);
$_SESSION['password'] = Trim ($_POST['username']);

??: ??? ????? ?? ??? ??

??????? ??? ?? sql ?? ???? ???? ??? ??? ???????? ??? ??? ??? ????? ?? ? ????. ??? ???? ???? ? ????.

???? ???? ??? ?? ???? ?????.

???? ???? ???? ?????. ??? ???